Design And Implementation Of Channel Estimation And Channel Equalization For Large Delay And Fading Communication System

Multipath spread and varying of channel are the two main issues need to be solved in wireless communication systems. A proper channel estimation and equalization method in some specific multipath fading channel will play an important role in the improvement of overall performance. This paper is committed to solve a practical problem encountered in engineering: to design channel estimation and equalization in a high-speed single-carrier aviation communication system. In high-speed single-carrier aviation communication system, the power of multipath are great, which will result in serious inter-symbol interference. More importantly, the number of symbols corresponding to the multipath delay is also large, making complexity of existing channel estimation and equalization methods increase drastically. That is to say, traditional methods can’t meet the engineering needs in these conditions.Aiming at high-speed single-carrier aviation communication system, this paper do research in key technologies of channel estimation and equalization applied to particular aviation channel and propose solutions applied to large delay and strong multipath interference in air-to-air communication. Then we will design software program based on hardware description language to solve multipath issue in FPGA. Main work of this paper is as follows:1. After systematic analysis of digital multiplexer and demultiplexer, low speed digital signal and pilot sequences and filling frame would be merged to high-speed signal in the transmitting terminal, and then in the receiving terminal, pilot sequences and filling frame would be removed.2. Proposed a channel estimation method taking use of the correlation of PN sequence. This method has low complexity and high accuracy and could be an ideal channel estimation method in large delay fading communication system.3. Based on the implemention of channel estimation, we resolved the multipath interference using decision feedback equalizer and resolved the equalization issue encountered in high-speed single-carrier aviation communication system.The anti-multipath system in this paper resolved multipath interference and could work well in bad external environment. The system has high application value and more research work on channel estimation and equalization could be launched.